"The proof is in the pudding, the proof is in the reach of these videos," he said.

"If you're getting reaches of over 100,000 people that is coming down to 5 cents per person being reached, of a political message, of being able to communicate with your own constituents, a letter costs $1.50 each."

Former rights commissioner's cyber spend

First-term Liberal MP Tim Wilson spent close to $25,000 creating a website after he was elected.

Mr Wilson won the Victorian seat of Goldstein at last year's federal election after spending two years as Australia's human rights commissioner.

One of his first acts as a new MP was to create a sleek website, which would cost taxpayers $24,925 in two half-payments of $12,462.50.

Mr Bandt's office said social media videos were a cost-effective way to spread a message.

"Compared to personally addressed mail, which could cost more than $1 per person reached, a single video can reach tens or hundreds of thousands," a statement from his office said.

"Adam has a large following on social media and we believe constituents, voters and supporters have an expectation that we communicate with them in a contemporary way."

What do the rules allow?

Professor John Wanna from the Australian National University said all the above examples were within the rules, paid for as part of parliamentarians' "Printing and Communications" allowance.

"They are within the rules but the rules themselves are very lax, they're basically a set of headings parliamentary business and electoral expenses, which are really not defined," he said.

The rules for social media are broad, specifying that material can be produced if:

The cost relates to a commercially provided service

The material is for parliamentary or electorate purposes

The material is not for party business or commercial purposes

Professor Wanna said social media was also a way to bypass the advertising ban, which prevents broadcasters from running political ads from midnight on the Wednesday before a state or federal election.

"It may be used to kind of stir up a bit of a moral panic — stir up a bit of an interest in a particular issue, pretend a member is under threat — and that you've all got to get out there and vote for them," he said.

He said work needed to be done for the regulation to catch up with the digital age.

"The rules could be tightened up, the rules are very simple and very few," he said.

"In essence, so long as you're not putting material out asking for people to vote you, or putting material out asking for people to donate to your campaign, then you can pretty much get away with anything else."